Electronic equipment involving semiconductive devices are essential for many modern applications. Technological advances in materials and design have produced generations of semiconductive devices where each generation has smaller and more complex circuits than the previous generation. In the course of advancement and innovation, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometric size (i.e., the smallest component that can be created using a fabrication process) has decreased. Such advances have increased the complexity of processing and manufacturing semiconductive devices.
In modern integrated circuit (IC) fabrication, on-chip capacitors are available for a myriad of applications, such as dynamic random access memories (DRAM), voltage controlled oscillators and operational amplifiers. The capacitors may be used for providing decoupling between circuits from undesired interference or noise resulting from the rest of the chip.
The capacitors are usually designed to possess a high aspect ratio in order to achieve a high density layout. However, as the chips are made progressively thinner, the rigidity and robustness of the wafer containing the chips may be more vulnerable to damage since the wafers along with embedded features fail to provide sufficient resistance to stress. Therefore, an improved structure and manufacturing method of capacitors are desired.